I fiddled with the excellent Android app Setting Profiles last Weekend, and by doing that, I think I have come up with some awesome rules and profiles to save a lot of battery power.
Finally I have a device that is near my dream device: a smartphone without the phone. I don't need the phone feature. Please note that at the end of the video I show how the app looks and my profiles and rules.
I'm sorry for the terrible video quality in the beginning, but it was very early in the morning and total black outside. SO no light at all. I have made the video brighter so you can see me.